Yeah that's the problem. 2x is too big and 1x is too small on 3200x1800. Luckily there's a workaround to scale text to 1.5x which for most purposes is fine.
I like 2x scale on the XPS 13 9350 (with 3200x1800). It results in a super sharp 1600x900 which is ideal for the 13.3" screen site.
Give KDE Neon a try. I use it as my daily driver on a Latitude 7370 with the 3200x1800 display.